1. Field of the Invention
This invention relates to medical devices used in irrigating and cleansing wound sites on patients, and is specifically related to splash shields for preventing the back splash of fluids from a wound during wound irrigation so that the wound fluids do not contact the attending medical caregiver.
2. Statement of the Art
It is well-known that wounds to the body which occur through injury or accident, through surgical procedure, or which are caused by compromised circulation, such as pressure ulcers, must often be cleansed to keep the wound free of bacteria and other deleterious matter which may compromise the rate at which the wound heals. Cleansing of the wound often involves irrigating the wound with a stream or spray of liquid, such as isotonic saline or other sterile solution. Current clinical practice guidelines indicate that an irrigation pressure of between four to fifteen pounds per square inch pressure is effective for the cleansing of pressure ulcers or other chronic wounds. That amount of pressure is sufficient for removal of foreign particles, debris and bacteria to thereby promote healing and minimization of infection or inflammation, yet low enough to avoid or minimize damage to regenerating granulation tissue in the wound. The guidelines also recommend the use of high pressure irrigation for mechanical debridement, in which case there are no limitations to the maximum amount of pressure that may be used to remove the devitalized tissue.
Delivery of the irrigating liquid to the wound site is usually accomplished by pumping liquid from a hypodermic syringe through an attached needle, or syringe connector, trained toward the wound site. Most of the liquid delivered to a wound site flows away from the wound site, and is usually collected in some manner, such as in a bowl or with absorbent material. However, some back splash of fluid and debris from the wound occurs, especially at higher pressures of liquid delivery. The liquid back splash contains not only irrigating liquid, but fluid from the wound and loose matter extracted from the wound--particularly in situations where wound irrigation is conducted for debridement of the wound. It is unpleasant and potentially dangerous to have the back splash liquid from the wound strike the medical personnel conducting the irrigation procedure or the patient, or to have the material contaminate the environment. Current OHSA guidelines regarding blood-bourne pathogens require the minimization of the splatter and splashing of blood and the creation of aerosols containing potentially contaminated body fluids. Therefore, shield devices have been developed in the art to protect the caregiver from being exposed to the back splash.
Examples of wound irrigating back splash shields are disclosed in U.S. Pat. No. 4,692,140 to Olson, U.S. Pat. No. 4,669,003 to Stamler, U.S. Pat. No. 4,898,588 to Roberts, U.S. Pat. No. 5,224,940 to Dann et al., U.S. Pat. No. Des. 344,133 to Stamler, U.S. Pat. No. Des. 345,016 to Stamler, U.S. Pat. No. 5,376,003 to Rizkalla, U.S. Pat. No. 5,441,174 to Sperry and U.S. Pat. No. 5,496,290 to Ackerman. Most of the shields disclosed in the referenced patents are rigid and are, therefore, unadaptable to the variation in wound shapes which occur. As a result, back splash liquid can still escape the confines of such shields. More importantly, rigid prior art shields can damage the regenerating tissue of a wound if the rigid circumferential edge of the shield is pressed against, scraped along, or otherwise contacted with the wound.
Most of the shields disclosed in the referenced patents are configured with a liquid delivery conduit which is positioned in alignment with a central longitudinal axis of the shield so that liquid delivery is strictly along that central longitudinal axis. The configuration of such devices requires the fluid delivery apparatus (i.e., typically a hypodermic syringe) to be positioned in vertical alignment with the wound to effectuate liquid delivery. The placement or positioning of a wound on a patient is not always so accommodating. For example, a wound on the back of a patient who cannot be moved or rotated significantly from a supine position requires the caregiver to position himself and the irrigation device at a difficult angle to reach the wound. Furthermore, even those shields which are configured to provide a fluid conduit which is not strictly oriented along a longitudinal axis of the shield are unable to be angularly adjusted to modify the direction of liquid delivery to the wound.
Clinical practice guidelines requiring an irrigation pressure of 4 to 15 psi for the effective cleaning of wounds also imposes an additional requirement for wound irrigating devices which is not addressed in prior art devices. It is left to the judgment of the caregiver to determine when and if the irrigating fluid is being delivered to the wound within the required range of pressure. The failure to irrigate the wound at the appropriate fluid pressure can adversely affect the health and healing of the wound, and ultimately the patient. The importance of proper irrigation is further complicated by the fact that some patients, such as elderly or frail patients, often have wounds that do not heal or the tissue does not regenerate rapidly. Thus, fluid delivered at too high a pressure may compromise the healing process, and fluid deliberately delivered at a lower pressure may be inadequate for cleaning the wound.
Using conventionally known wound irrigating devices, the caregiver must depress with the thumb and fingers the plunger of a 35 cc hypodermic syringe filled with irrigating fluid and fitted with a 19 gauge needle of one and one half inches in length to produce an 8 psi delivery of irrigating fluid. That methodology assumes that all caregivers have the same degree of manual strength to depress the plunger and does not take into consideration that the caregiver's hand tires after repeated fillings and evacuations of the syringe in a single wound irrigating episode, thereby leading to less and less pressure being applied to depression of the plunger. Another factor leading to uneven or inconsistent fluid pressure at delivery is the mechanics of hand movement leading to different pressure being applied to the plunger when the plunger is fully extended from the syringe barrel (and the thumb is displaced farther from the fingers) as opposed to when the plunger is almost fully positioned in the barrel (and the thumb is closer to the fingers).
Thus, it would be beneficial to the art to provide a wound irrigation apparatus which facilitates delivering irrigation fluid at a specified pressure and which includes a splash shield which is safe for use in proximity to a wound, which is adaptable to the differences in wound dimension and body contour, and which provides a degree of angular adjustability to facilitate delivery of the irrigating fluid to a wound site while still providing protection from the back splash of fluid and other debris from the wound.